The Driver and Vehicle Licensing Agency (DVLA) only refund whole unused months of tax. Therefore when a vehicle changes keeper, both the old keeper and the new keeper pay the same months tax. This is clearly wrong.
After a recent purchase of a vehicle that was delivered to my door by the previous owner and stored in a garage for a couple of weeks, I decided to tax it and use it on the roads. However when I went online to pay the Vehicle Excise Duty (VED), the amount charged was backdated to the previous month. This is not right, as the previous month is paid for by the previous keeper (and was not used on the roads during my new keepership anyway). Once paid, this could not be corrected. The person I spoke to at DVLA explained this to me and then rather rudely hung-up the phone.
So when transferring another vehicle a while later, I waited until the vary last day of the month to transfer it so that I received a full refund for the unused tax and the new keeper could start their tax the following day. However, even by doing this the new keeper's VED would have been backdated to the beginning of the previous month thus both of us paying the months tax. Again, this is clearly wrong.
To resolve this, I got the new keeper to submit a Statutory Off Road Notification (SORN) on the day of transfer and then they applied for the new tax to start the following day. To do this legally, the new keeper needed to make sure that the vehicle was off-road overnight. However to complicate it further, the DVLA website does not allow a vehicle to be taxed within 5 days of a SORN being made and this had to be done with a visit to the post office.
Another way around this would be for the old keeper to take the vehicle off road, SORN the vehicle, obtain a full refund of the unused months and then transfer the vehicle the following month. The new keeper would be able to apply for VED commencing at the beginning of the new month.
It seems to me, they have made it excessively difficult for vehicle keepers to pay the correct tax when there is a transfer of keeper. It may seem petty, but I think it is important that everyone pays the correct taxes.